Which region of the ultraviolet spectrum is identified as most harmful at ground level?

The region of the ultraviolet spectrum that is most harmful at ground level is identified as UV-B. UV-B radiation has a shorter wavelength than UV-A and is more energetic, making it capable of causing damage to living cells, including skin and eye tissues. This type of radiation is responsible for sunburn and plays a significant role in the development of skin cancer, which underscores its harmful nature.

While UV-C is even more energetic than UV-B, it is largely absorbed by the ozone layer and does not reach the Earth's surface in significant amounts under normal atmospheric conditions. UV-A, while it can penetrate the skin more deeply and contribute to aging and skin damage, is not as energetically harmful as UV-B. Visible light, on the other hand, does not have harmful effects in the same way ultraviolet radiation does, thus it's not categorized under harmful UV radiation.

Understanding the implications of UV-B exposure is crucial for developing protective measures, such as sunscreen and UV-blocking materials, to safeguard against its detrimental health effects.